I like running several Sandboxies concurrent (thanks in part to Yahoo/ATT merger), but would like to not have to close a sandbox but to Pause one and then re-animate as necessary in order to reduce resourses when not actively using a sandbox; a dorment feature if you will. Everytime I launch a Sandbox from scratch, it takes more time then I would wish; just pausing the sandbox (maybe a rightclick feature on the sandbox session itself) would mean that when I do want to be active with it, it will be pretty much instant. Just wondering if this feature would be possible.

Since the programs are runnning native speed and assuming you have a modern system, these apps shouldn't be that heavy to need such a feature. Pausing is more of a virtual machine option which is probably not possible in the context and purpose of Sandboxie. But just wait and see what Tzuk has to say about it.

Thanks cool tzuk. Again, my main motivation is having multiple email sessions up since Yahoo mail and AT&T mail can not co-exist without using something like Sandboxie and I like to peruse my various emails, but I don't like the pushed ads that they continuingly do which take some bandwith and stuff. Closing a session then reopening it only takes 10s of seconds so no big deal. Normally, I just live with the consequences and keep them both open.

I think this is a great feature and you should add this to Sandboxie.
Here's a use case:
I have multiple applications which say are in logged in state, like email clients, browsers and so on.
To have them running continuously would be a waste of CPU/memory resources and is not desirable.
I can have them running in multiple sandbox and pause them all and have one or few run for few minutes and pause them back.

I challenge that this is a big implementation effort.
Since Sandboxie anyway would have process level control for all the processes it spawns, all it has to do is:
for each process in sandbox, get list of threads of the process, set the thread to Suspend noting which ones it actually suspended.

Later on on Resume:
For each process in sandbox, get the list of suspended threads, set them to RESUME

I don't see this as an issue with any value. If you are using an email client, and not doing anything with it, yes it takes memory, but nothing other than that. Memory shouldn't be an issue today with the amount of memory that can be had on the cheap.